Low weight modular carpet components and methods of making the same

ABSTRACT

A low-weight carpet tile and process for making the same, wherein the carpet tile comprises a facecloth having a plurality of face yarns tufted through a primary backing, an extruded polymer secondary backing layer, and a reinforcing scrim layer partially embedded within the extruded polymer secondary backing layer. The top surface and bottom surface of the carpet tile are defined by the facecloth and the reinforcing scrim layer, respectively. A polymer-based resin is extruded onto the facecloth to form an at least substantially uniform secondary backing layer, and the reinforcing scrim layer is laid onto the extruded polymer secondary backing layer while the extruded polymer secondary backing layer remains above a softening temperature for the resin. The entire multi-layer web is then passed through a nip to embed the reinforcing scrim layer into the extruded polymer secondary layer, and the entire web is chilled.

BACKGROUND

The installation techniques traditionally used to install modular carpetcomponents such as carpet tiles puts a large emphasis on the need toensure that each component is individually flat when installed. Whereasthe edges of larger broadloom carpet installations may be positionedadjacent walls and/or may be specifically pinned to a subfloor, theedges of at least some smaller carpet tiles are generally exposed(possibly in the center of a room or high-traffic area) and may not bedirectly secured relative to their respective neighboring tiles. Thus,manufacturers of carpet tiles must ensure that these tiles do not curl(such that the carpet tile edges curl upward away from the subfloor) ordome (such that the middle of the carpet tile moves upward away from thesubfloor) once installed. Each of these possible defects may create triphazards for individuals walking along the tiled floor, or may createunsightly gaps between adjacent tiles. Even when each carpet tile isindividually secured to the underlying subfloor (e.g., via an adhesive),internal forces within the carpet tile tending to curl or dome may causeportions of the tile to break away from the adhesive and the subfloor.

Historically, carpet tiles have been relatively heavy to help ensureeach tile remains flat against a subfloor. The weight of each tile isthought to overcome any internal forces tending to curl or dome thecarpet tile, thereby ensuring that the tile itself remains flat onceinstalled. However, because carpet tiles are relatively heavy,particularly in comparison to similarly-sized broadloom carpet,transportation and installation of carpet components may be relativelyexpensive and/or time consuming due to the additional effort needed tomaneuver each weighty carpet tile. The weight of carpet tiles has alsolimited their usage to applications in which weight, once installed, isgenerally unimportant, such as residential or commercial buildings.Carpet tiles have been particularly challenging for use in the airlineindustry, in which weight is of paramount importance during theselection of components for installation in aircraft.

Accordingly, a need exists for low-weight and durable carpet tileshaving desirable flatness characteristics.

BRIEF SUMMARY

Various embodiments are directed to a low-weight carpet tile having atotal weight of less than 60 ounces per square yard. The carpet tilecomprises a tufted primary backing defining a top wear surfacecomprising a plurality of tufted fibers. The opposite, backside of theprimary backing may be coated with a pre-coat layer to lock the carpettufts into the primary backing. The coated primary backing has anextruded polymer secondary backing secured thereto, and the extrudedpolymer secondary backing has a reinforcing scrim layer embeddedpartially therein to define the bottom surface of the carpet tile.

Various embodiments are directed to a carpet tile comprising a faceclothcomprising a primary backing and a plurality of face yarns extendingthrough the primary backing, wherein the facecloth defines an uppersurface of the carpet tile; an extruded polymer secondary backing layerbonded to the facecloth; and a reinforcing scrim layer bonded to abottom surface of the extruded polymer secondary backing, wherein thereinforcing scrim layer defines in part a bottom surface of the carpettile. The reinforcing scrim layer may comprise a plurality of fiberscomprising at least one of glass fibers or polymer fibers. The pluralityof fibers of the reinforcing scrim layer may be arranged in a nonwovenconfiguration.

Moreover, the extruded polymer secondary backing may comprise apolyolefin, for example, in an amount between about 10-40 wt % of theweight of the extruded polymer secondary backing. The extruded polymersecondary backing may additionally comprise an inert filler material inan amount between about 20-80 wt % of the weight of the extruded polymersecondary backing. Moreover, the facecloth may additionally comprise aprimary backing pre-coat layer between the primary backing layer and theextruded polymer secondary backing layer.

Certain embodiments are directed to a method of manufacturing a carpettile, the method comprising providing a facecloth, wherein the faceclothcomprises a primary backing having a plurality of face yarns extendingthrough a facecloth; forming a multi-layer construction comprising thefacecloth and a backing construction secured on a first side of thefacecloth by: extruding a polymer sheet onto the first side of thefacecloth; pressing a fibrous reinforcing scrim layer partially into theextruded polymer sheet to bond the fibrous reinforcing scrim layer tothe bottom surface of the extruded polymer sheet such that the fibrousreinforcing scrim layer defines at least a portion of a surface of thecarpet tile; and, in certain embodiments, chilling the multi-layerconstruction. In certain embodiments, extruding the polymer sheetcomprises extruding a polyolefin-based resin comprising between about10-40 wt % polyolefin and between about 20-80 wt % of a filler material,measured as portions of the weight of the resin. Moreover, pressing thefibrous reinforcing scrim layer partially into the extruded polymersheet comprises pressing a fiber mat partially into the extruded polymersheet.

Moreover, certain embodiments are directed to a carpet tile secondarybacking resin comprising: a polyolefin material provided in the range ofbetween about 10-40 wt % of the weight of the resin; an inert fillermaterial provided in the range of between about 50-80 wt % of the weightof the resin; a viscosity modifier provided in the range of betweenabout 1-3 wt % of the weight of the resin; and one or more additionaladditives collectively provided in the range of between about 0.5-15 wt% of the weight of the resin. In certain embodiments, the polyolefinmaterial comprises at least one of 1-propene, ethylene copolymer;ethylene-propylene copolymer; or propylene homopolymer.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale, and wherein:

FIG. 1 is a side cutaway view showing various components of a carpettile according to one embodiment;

FIG. 2 is a schematic diagram of a portion of a manufacturing lineutilized to produce carpet tiles according to various embodiments; and

FIG. 3 is a flowchart showing various steps involved in production of acarpet tile according to various embodiments.

DETAILED DESCRIPTION

The present disclosure more fully describes various embodiments withreference to the accompanying drawings. It should be understood thatsome, but not all embodiments are shown and described herein. Indeed,the embodiments may take many different forms, and accordingly thisdisclosure should not be construed as limited to the embodiments setforth herein. Rather, these embodiments are provided so that thisdisclosure will satisfy applicable legal requirements. Like numbersrefer to like elements throughout.

Various embodiments are directed to a low-weight, dimensionally stablecarpet tile that is resistant to both doming and curling. The carpettile is a multi-layer carpet tile comprising a facecloth (comprising aprimary backing, face yarn, and optionally a pre-coat layer), bonded toa backing construction comprising an extruded polymer secondary backinglayer and a fibrous reinforcing scrim layer (e.g., woven or nonwoven)bonded to (e.g., partially embedded in) the extruded polymer secondarybacking layer to define, at least in part, the bottom surface of thecarpet tile. The low weight carpet tile product has a total weight ofless than 60 ounces per square yard while remaining resistant todeformation (dimensional deformation, curling, or doming) due at leastin part to the location of the reinforcing scrim layer on the bottomsurface of the carpet tile. Moreover, at least a portion of thereinforcing scrim layer is exposed on the bottom surface of the carpettile (e.g., protruding from the bottom surface of the extruded polymersecondary backing), and at least a portion of the fibers of thereinforcing scrim layer may be coated with a nonirritating coating toprevent skin irritation for installers of the carpet tiles.

Carpet Tile

Referring to the figures, in which like numerals refer to like elementsthrough the several figures, FIG. 1 is a cross sectional view of acarpet tile 100 in accordance with various embodiments of the presentinvention. In the illustrated embodiment, the carpet tile 100 includesface yarn 105, which may be either tufted or woven into a primarybacking 110 to form a facecloth 111. The face yarn 105 may be made fromvarious materials, both natural and synthetic, such as nylon 6, nylon 6,6, cotton, wool, nylon, acrylic, polyester, polyamides, polypropylene,and other polyolefins. The face weight of the face yarn 105 can beapproximately 5 ounces per square yard to approximately 50 ounces persquare yard.

The primary backing 110 may be formed from a substrate such as a wovensubstrate, a tape yarn substrate, and/or other substrate constructionthat imparts stability to the carpet tile 100. The substrate may be madefrom a polyester, such as poly(ethylene terephthalate) [PET],poly(trimethylene terephthalate) [PTT], poly(butylene terephthalate)[PBT], poly(ethylene terephthalate-co-isophthalate), poly(ethylenenaphthalenedicaroxylate) [PEN], and copolymers thereof, and/orcombinations thereof, with PET being preferred. In certain embodiments,the primary backing 110 may comprise a low melt polyester materialconfigured to bind the various fibers together upon application of heatto the primary backing. The substrate may also comprise sheathed fibers,which may comprise a polyester core surrounded by a polyamide and/orpolyolefin sheath. Typically, the polyester core may be made from PET,PTT, PBT, PEN, poly(ethylene terephthalate-co-isophthalate) andcopolymers thereof. The polyamide sheath may be made frompolycaprolactam [nylon 6], poly(7-heptanamide) [nylon 7],polycapryllactam [nylon 8], poly(9-nonanamide) [nylon 9],poly(tetramethylene adipamide) [nylon 4,6], poly(hexamethyleneadipamide) [nylon 6,6], poly(methylene-4,4′-dicyclohexylenedodecanediamede), poly(1,4-cyclohexylenedimethulene suberamide),poly(m-phenylene isophthalamide), and poly(p-phenylene terephthalamide),with polycaprolactam [nylon 6] being the preferred polyamide. In certainembodiments, the primary backing 110 may be formed using a wovensubstrate using any conventional natural or synthetic woven material,such as cotton, jute, rayon, paper, nylon, polypropylene and otherpolyolefins, polyamides, polyesters.

The face yarn 105 may be tufted through the primary backing 110 so thatthe ends of the face yarn 105 extend in an outwardly direction from thetopside of the primary backing 110 to form an upper surface of thecarpet tile 100. Typically the face yarn is tufted into the primarybacking 110 at a weight of approximately 2.6 ounces per square yard toapproximately 5.9 ounces per square yard, and more preferablyapproximately 3 ounces per square yard. The tufting may be performedusing conventional techniques that are well known in the art.Furthermore, the tufted face yarn 105 loops may be left as uncut to forman uncut pile carpet, cut to form a cut pile carpet, or partially cut toform a tip sheared carpet, as is well known in the art.

In certain embodiments, the facecloth 111 includes a pre-coat layer 115that is applied to a bottom surface of the primary backing 110. Thepre-coat layer 115 penetrates the tufted face yarn 105 and encapsulatesindividual ends of the yarn bundles to at least partially bind thetufted face yarn 105 to the primary backing 110. This may prevent oneend of an individual fiber from being pulled out of the carpet backingduring the manufacturing process. The pre-coat layer 115 may also act asa tackifier to provide an acceptable binding surface for a subsequentpolymer layer. In an exemplary embodiment, the pre-coat layer 115comprises a hot melt adhesive (HMA) that contains a tackifying resin oragent alone or in combination with polyethylene. In various embodiments,the pre-coat layer 115 comprises an aqueous-latex based polymerconfigured to support the face yarn 105 within the primary backing 110upon drying. In certain embodiments, the pre-coat layer 115 comprisesbutadiene acrylate based polymers, vinyl acetate ethylene, vinylacetate-ethane copolymers, and/or latex based compounds. The pre-coatlayer 115 may include one or more other compositions, such as inertfiller materials (e.g., fly ash) as discussed in reference to theextruded polymer secondary backing layer 120 herein.

The pre-coat layer 115 may be applied to a bottom surface of the primarybacking 110 in the range of approximately 2 ounces per square yard toapproximately 20 ounces per square yard, and more preferably in therange of approximately 8 ounces per square yard to approximately 12ounces per square yard.

Disposed on a bottom surface of the facecloth 111 is a backingconstruction comprising an extruded polymer secondary backing layer 120and a reinforcing scrim layer 130. The backing construction is arrangedsuch that the extruded polymer secondary backing layer 120 is positionedbetween the reinforcing scrim layer 130 and the facecloth 111. In suchan embodiment, a first (top) side of the extruded polymer secondarybacking layer 120 is bonded to the facecloth 111 and a second (bottom)side of the extruded polymer secondary backing layer 120 is bonded tothe reinforcing scrim 130. The extruded polymer secondary backing layer120 is embodied as a resin comprising one or more componentscollectively configured to give the resulting carpet tile 100 a flatoverall appearance without substantial doming (a central portion of thecarpet tile 100 rising relative to the edges such that a top surface ofthe carpet tile 100 is convex) or curling (the edges of the carpet tile100 rising relative to the central portion such that a top surface ofthe carpet tile 100 is concave). The resin of the extruded polymersecondary backing layer 120 may comprise a polyolefin or a mixture ofone or more polyolefins together with one or more other polymers. Forexample, the resin may comprise polyethylene and/or polypropylene. Asspecific examples, the polyolefin polymer is embodied as 1-propene,ethylene copolymer or ethylene-propylene copolymer. In certainembodiments, the resin of the extruded polymer secondary backing layer120 comprises the polyolefin or polyolefin mixture in an amount betweenabout 10-40 wt % of the resin of the extruded polymer secondary backinglayer 120 (and of the extruded polymer secondary backing layer 120itself).

The resin extruded polymer secondary backing layer 120 may additionallycomprise one or more additives, such as an inert filler material, acolorant, an antioxidant, a tackifier, a viscosity modifier, a flameretardant, and/or the like.

The inert filler material may constitute the majority of the resin ofthe extruded polymer secondary backing layer 120 (by weight), and mayfunction as a low cost material that adds weight to the extruded polymersecondary backing layer 120 to aid in forming an at least substantiallyflat carpet tile 100. For example, the inert filler material mayconstitute between about 20-80 wt % of the resin and/or the extrudedpolymer secondary backing layer 120.

The inert filler material may be made from carbonates such as calciumcarbonate (CaCO₃), cesium carbonate (CsCO₃), strontium carbonate(SrCO₃), and magnesium carbonate (MgCO₃); sulfates such as bariumsulfate (BaSO₃); oxides such as iron oxide (Fe₂O₃ or Fe₃O₄), aluminumoxide (Al₂O₃), tungsten oxide (WO₃), titanium oxide (TiO₂), siliconoxide (SiO₂); silicates, such as clay; metal salts; fly ash and thelike.

Additionally, the inert filler material may be made from post-consumerproducts, such as post-consumer glass, post-consumer carpets and/orother post-consumer recycled materials. In cases where the inert filleris made from post-consumer glass, the post-consumer glass is ground intoa fine glass powder before it is added as filler. The glass cullet maybe made from automotive and architectural glass, also known as plateglass, flint glass, E glass, borosilicate glass, brown glass (bottleglass), green glass (bottle glass), and coal fly ash, or a combinationthereof. In the case where post-consumer carpet is used as the inertfiller material, the post-consumer carpet maybe ground into a finecullet and added to the hot melt adhesive. In addition to thepost-consumer carpet, remnants and trimmings of carpet (e.g., comprisingtrim waste from cutting carpet tiles from rolls of carpet, sometimesreferred to as window waste), fine waste fibers that are a result of theshearing process, and the like, that are produced as a by-product duringthe manufacturing process may also be used to form the inert fillermaterial.

The filled or unfilled polymer may also contain a colorant, such ascarbon black or another colorant(s) to provide color and increase theopaqueness of the extruded polymer secondary backing layer 120.Typically, the colorant may be present in an amount less than or equalto approximately 1 wt % the filled or unfilled resin and extrudedpolymer secondary backing layer 120. For example, the colorant may bepresent in an amount between about 0.1-0.5 wt % of the extruded polymersecondary backing layer 120. As a specific example, the colorant may bepresent in an amount of approximately 0.1 wt % of the resin and theextruded polymer secondary backing layer 120.

Moreover, to reduce the possibility of thermo-oxidation degradation, thepolymer may also contain one or more antioxidants. Some suitableantioxidants include, but are not limited to amines, 2,2′-methylenebis-(4-methyl-6-tert-butylphenol), 2,4,6-tri-tert-butylphenol,2,6-di-tert-butyl-4-methylphenol, 4,4′-thio-bis-(6-tert-butyl-m-cresol),butylated hydroxy anisole, butylated hydroxy toluene, bis(hydrogenatedtallow alkyl),oxide; tris(2,4-ditert-butylphenyl)phosphite and 1,3,5triazine-2,4,6(1H, 3H, 5H)-trione,1,3,5,tris ((3,5 (1dimethylethyl))-4-hydroxyphenyl)methyl. Typically, the antioxidant maybe present in the filled or unfilled extruded polymer secondary backinglayer 120 in an amount less than or equal to approximately 2 wt % of theresin and/or the extruded polymer secondary backing layer 120, such asbetween about 0.05-0.5 wt % of the resin and/or the extruded polymersecondary backing layer 120.

Moreover, the extruded polymer secondary backing layer 120 mayadditionally include one or more tackifiers to aid in forming a strongmechanical bond with the pre-coat layer 115 (if present), the primarybacking 110, and/or the reinforcing scrim layer 130 discussed in furtherdetail below.

The resin of the polymer secondary backing layer 120 may additionallyinclude one or more viscosity modifiers and/or compatibilizers, such as,for example, olefins of higher or lower molecular weight than the resindiscussed herein or ethylene maleic anhydride copolymer, to ensureproper flow and bonding of the resin within filler and polymers whenapplying onto a facecloth 111. The viscosity modifier may be present inan amount between about 0.1-3 wt % of the resin and the extruded polymersecondary backing layer 120.

In certain embodiments, the resin of the extruded polymer secondarybacking layer 120 may additionally comprise one or more flameretardants, such as, but not limited to, aluminum trihydrate (ATH) ormagnesium hydroxide (MgOH) for applications where flame-retardancy isdesired. One or more flame retardants may be necessary to comply withapplicable regulations regarding the installation and/or usage of carpettiles in certain applications, for example, when such carpet tiles areinstalled in transportation vehicles (e.g., buses, aircraft, and/or thelike).

Example resins of the extruded polymer secondary backing layer 120 areshown in tables 1 and 2, below, with example amount ranges that may beincluded for each component. The inventors found that both of theseexample extruded polymer secondary backing layer 120 formulationsprovided a lightweight carpet tile having a strong mechanical bondbetween the various layers of the carpet tile 100 and a substantiallyflat carpet tile profile.

TABLE 1 Component wt % range (of resin) 1-propene, ethylene copolymer20-40 Primary antioxidant 0.1-0.3 Secondary antioxidant 0.05-0.15Ethylene maleic anhydride copolymer 1-3 Calcium carbonate 60-80 Carbonblack concentrate 0.1-0.5

TABLE 2 Component wt % range (of resin) Ethylene-propylene copolymer10-30 Propylene homopolymer 0.1-3   Tackifier  1-15 Ethylene maleicanhydride copolymer 0.1-3   Calcium carbonate 48-80 Carbon blackconcentrate 0.1-0.5

Referring again to FIG. 1, the carpet tile 100 additionally comprises areinforcing scrim layer 130 partially embedded within the extrudedpolymer layer 120 to define, at least in part, the bottom surface of thecarpet tile 100. The reinforcing scrim layer 130 imparts dimensionalstability to the finished carpet tile 100. Because the reinforcing scrimlayer 130 is positioned on the bottom surface of the carpet tile 100,the reinforcing scrim layer 130 provides additional support againstcurling and/or doming of the carpet tile.

The reinforcing scrim layer 130 may comprise a fibrous material providedin either a woven or non-woven configuration. Particularly when providedon the bottom surface of the carpet tile 100, a woven fibrousreinforcing scrim layer 130 contributes to providing desirable flatnesscharacteristics to the resulting carpet tile 100 while nonwoven fibrousmaterials aid in preventing shrinkage or expansion of the resultingcarpet tile 100. The desirable flatness characteristics may be at leastsubstantially free from doming (a central portion of the carpet tile 100rising relative to the edges to provide a convex top surface of thecarpet tile 100) or curling (the edges of the carpet tile 100 risingrelative to the central portion to provide a concave top surface of thecarpet tile 100) that traditionally results from providing a polymerbacking on a carpet tile 100. As certain polymers cool and/or harden ona back of a carpet tile 100, those polymers tend to shrink and pullother portions of the carpet tile 100 (causing the carpet tile to deformand dome) or expand and pull other portions of the carpet tile 100(causing the carpet tile to deform and curl). Placing a reinforcingscrim layer 130 on the bottom portion of carpet tile 100 counteracts thedeformation forces on the carpet tile 100 caused by the polymer backingcooling and hardening. Given these two distinct characteristics of wovenand nonwoven fibrous scrim materials, certain carpet tiles 100 maycomprise a reinforcing scrim layer 130 comprising both woven andnonwoven fibrous materials.

The fibrous materials themselves may constitute any number of natural orsynthetic materials. For example, the fibrous materials may be embodiedas glass fibers, which may be coated with a nonirritating coating (e.g.,a thermoplastic or thermoset coating), such as a polyethylene. Thenonirritating coating may be applied to the fibers individually (e.g.,to create a sheathed fiber) or the nonirritating coating may be appliedto the woven or non-woven reinforcing scrim layer 130. For example, thenonirritating coating may be applied to a bottom surface (e.g., theexposed bottom surface) of the reinforcing scrim layer 130. Thenonirritating coating may prevent installers from coming into contactwith irritating fibrous materials while laying the carpet tiles 100. Thefibrous material may additionally and/or alternatively comprise one ormore polymer based fibers, such as polyester fibers, polyamide fibers,polyurethane fibers, combinations thereof, and/or the like. For example,the polymer fibers may comprise polypropylene fibers, polyethylenefibers, sheathed polymer fibers (e.g., having a polyethylene core and anylon or polypropylene sheath), and/or the like. As yet another example,the fibrous material may comprise a composite of polymer-based fibersand other fibers (e.g., glass fibers). Such a composite may compriselayers of non-woven and/or woven layers (e.g., a first layer comprisinga polymer-based fiber material and a second layer comprising a glassfiber material).

Method of Manufacture

FIG. 2 is a schematic diagram of a portion of an example carpet tilemanufacturing line that may be utilized to construct a carpet tile 100as discussed herein, and FIG. 3 is a flow chart of an example method forconstructing the carpet tile 100 according to certain embodiments. Asdiscussed herein, the carpet tiles 100 may be manufactured as a portionof a continuous web and later cut into desired tile shapes and sizes.However, it should be understood that carpet tiles 100 may bemanufactured according to any of a variety of manufacturing processes,such as a batch process in which each multi-layer carpet tile 100 isconstructed as a separate component.

As shown in FIG. 2, the process begins by providing a facecloth 111having a plurality of face yarns 105 extending through a primary backing110 (as indicated at Block 301 of FIG. 3). The facecloth 111 canoptionally have a pre-coat layer disposed on a backside of the primarybacking 110. As discussed herein, the topside of the facecloth 111ultimately forms the top surface of the completed carpet tile 100. Asmentioned, the tufted primary backing 110 is provided as a continuousweb, which may be threaded along a web travel path defined by aplurality of rollers (e.g., powered rollers and/or idler rollers). Incertain embodiments, the facecloth 111 may have a width between 72-80inches, although it should be understood that the facecloth 111 may haveany width with suitable production equipment.

As shown in FIG. 2, the facecloth 111 is advanced along the web travelpath in an inverted orientation with the backside of the facecloth 111facing upward, as indicated at Block 302 of FIG. 3. The facecloth 111 isadvanced past one or more extruder heads 220 configured to extrude acontinuous sheet of a resin having an at least substantially uniformthickness onto the backside of the facecloth 111 to form the extrudedpolymer secondary backing layer 120, as indicated at Block 303. Incertain embodiments, the extruder head 220 may comprise a single,elongated extrusion die tip opening extending across the entire width ofthe facecloth 111 such that the resin is extruded as a continuous sheetfrom the extruder head 220. Alternatively, the resin may be extrudedfrom a plurality of extruder heads 220 positioned across the width ofthe web travel path. The plurality of extruder heads may be spaced suchthat the resin flows together to form an at least substantiallycontinuous extruded polymer secondary backing layer 120 having an atleast substantially uniform thickness across the width of the facecloth111.

The one or more extruder heads 220 may be supplied by one or moreextruders (e.g., single screw extruders and/or dual-screw extruders)configured to combine the various components of the resin prior toextrusion to form the extruded polymer secondary backing layer 120. Oncecombined, the extruders and one or more extruder heads 220 provide theat least substantially continuous sheet of resin onto the bottom surfaceof the facecloth 111 at a temperature between about 275-500 degreesFahrenheit and at a weight of between about 8-35 ounces per square yard.In embodiments in which the facecloth 111 comprises a hot melt pre-coatlayer 115, the resin may be applied to the facecloth 111 while thepre-coat layer 115 is sufficiently hot (as may be the case with a hotmelt adhesive) so as to retain a tacky characteristic (e.g., while thepre-coat layer material remains above its softening point) to improvethe mechanical bond strength between the facecloth 111 and the extrudedpolymer secondary backing layer 120. However, it should be understoodthat the resin need not be applied to the facecloth 111 while a pre-coatlayer 115 remains hot in embodiments that do not utilize a hot meltadhesive pre-coat layer 115 (e.g., embodiments without a pre-coat layer115 and embodiments using an aqueous latex-based pre-coat layer 115).

After extruding the resin of the extruded polymer secondary backinglayer 120 onto the facecloth 111, the reinforcing scrim layer 130 islaid onto the exposed bottom surface of the extruded polymer secondarybacking layer 120 as indicated at Block 304 of FIG. 3. The extrudedpolymer secondary backing layer 120 remains above the resin softeningpoint when the reinforcing scrim layer 130 is laid onto the exposedsurface of the extruded polymer secondary backing layer 120, and theentire multi-layer web (including the facecloth 111, the extrudedpolymer secondary backing layer 120, and the reinforcing scrim layer130) is passed through a nip 250 comprising two rollers positioned onopposite sides of the web travel path to compress the multi-layer weband to provide strong bonds between adjacent layers of the carpet tile100. During compression, the extruded polymer secondary backing layer120 is bonded to the facecloth 111, and the reinforcing scrim layer 130is bonded to (e.g., embedded partially within) the extruded polymersecondary backing layer 120 (as indicated at Block 305). The reinforcingscrim layer 130 remains partially exposed, such that the reinforcingscrim layer 130 defines at least a portion of the bottom surface of theresulting carpet tile 100.

After the moving multi-layer web passes through the nip 250, the webpasses through one or more chilling rollers 260 to cool and harden theextruded polymer secondary backing layer 120 (shown at Block 306). Forexample, the one or more chilling rollers 260 may be collectivelyconfigured to chill the extruded polymer secondary backing layer 120 toapproximately room temperature (between about 75-80 degrees Fahrenheit).

The cooled multi-layer construction may then be passed to a tile cuttingmechanism configured to cut the multi-layer web into a plurality ofindividual carpet tiles or to a take-up roller 270 for storage. Forexample the web may be passed into a die cutter to cut the material webinto market-size carpet tiles 100 (e.g., 18″×18″, 24″×24″, or 36″×36″).Alternatively, the material web may be taken onto a large diameter(e.g., 8-foot diameter) drum where it can be taken to an off-line diecutting station for further processing into carpet tiles 100.

The resulting multi-layer construction (which may be cut into individualcarpet tiles 100) has an overall thickness that is less than similarcarpet tiles having a plurality of backing layers while retainingdesirable flatness characteristics of the carpet tile 100. This permitsa larger number of carpet tiles 100 to be stacked in a single carton, ona single pallet, and/or the like. Moreover, the resulting carpet tiles100 have a lower overall weight than similar carpet tiles having aplurality of backing layers. The decreased volume (due to the decreasedthickness) and decreased weight lowers transportation and installationcosts associated with carpet tiles 100 according to various embodimentswhile retaining desirable aesthetic characteristics once installed.

Example 1

One example low-weight carpet tile was manufactured according to themethodology discussed herein. The example carpet tile comprises afacecloth 111 comprising a primary backing layer 110 having a weight ofat least approximately 4 ounces per square yard, and having face yarns105 tufted therethough at a weight of at least approximately 14 ouncesper square yard. The tufted primary backing is coated with a pre-coatlayer 115 having a dry weight of at least approximately 12 ounces persquare yard.

The facecloth 111 is passed under an extruder head 220 as a part of acontinuous web, where the resin of the extruded polymer secondarybacking layer 120 is extruded onto a backside of the facecloth 111 (suchthat the resin is extruded onto the exposed surface of the pre-coatlayer 115) to form the extruded polymer secondary backing layer 120. Inthis example, the extruded polymer secondary backing layer 120 comprisesa resin mixture of the components listed in Table 3, heated to atemperature of 325-475 degrees Fahrenheit for extrusion.

TABLE 1 Component wt % 1-propene, ethylene copolymer 29.80 Primaryantioxidant 0.13 Secondary antioxidant 0.07 Ethylene maleic anhydridecopolymer 2.00 Calcium carbonate 67.90 Carbon black concentrate 0.10

The resin is extruded in a continuous sheet onto the facecloth 111 tocreate an at least substantially uniform extruded polymer secondarybacking layer 120 having an at least substantially uniform thickness.

Before the extruded polymer secondary backing layer 120 cools to atemperature below the softening point of the resin, a fiberglassnonwoven reinforcing scrim layer 130 is laid onto the exposed surface ofthe extruded secondary backing layer 120, and the entire multi-layer webis passed through a nip 250 and through one or more chilling rollers 260to embed the reinforcing scrim layer 130 into the extruded polymersecondary backing layer 120 and to cool and harden the extruded polymersecondary backing layer 120. The cooled web is then cut into individualcarpet tiles 100 for evaluation.

It was found that the carpet tile 100 provided according to this exampleconstruction exhibited exceptional flatness and dimensional stabilitycharacteristics, while retaining a total weight of approximately between40-70 ounces per square yard, and preferably approximately between 54-57ounces per square yard, such as at least approximately 55 ounces persquare yard.

Example 2

One example low-weight carpet tile was manufactured according to themethodology discussed herein. The example carpet tile comprises afacecloth 111 comprising a primary backing layer 110 having a weight ofat least approximately 4 ounces per square yard, and having face yarns105 tufted therethough at a weight of at least approximately 14 ouncesper square yard. The tufted primary backing is coated with a pre-coatlayer 115 having a dry weight of at least approximately 12 ounces persquare yard.

The facecloth 111 is passed under an extruder head 220 as a part of acontinuous web, where the resin of the extruded polymer secondarybacking layer 120 is extruded onto a backside of the facecloth 111 (suchthat the resin is extruded onto the exposed surface of the pre-coatlayer 115) to form the extruded polymer secondary backing layer 120. Inthis example, the extruded polymer secondary backing layer 120 comprisesa resin mixture of the components listed in Table 3, heated to atemperature of about 325-475 degrees Fahrenheit for extrusion.

TABLE 2 Component wt % Ethylene-propylene copolymer 19.9 Propylenehomopolymer 2.0 Tackifier 5.0 Ethylene maleic anhydride copolymer 3.0Calcium carbonate 70 Carbon black concentrate 0.1

The resin is extruded in a continuous sheet onto the facecloth 111 tocreate an at least substantially uniform extruded polymer secondarybacking layer 120 having an at least substantially uniform thickness.

Before the extruded polymer secondary backing layer 120 cools to atemperature below the softening point of the resin, a fiberglassnonwoven reinforcing scrim layer 130 is laid onto the exposed surface ofthe extruded secondary backing layer 120, and the entire multi-layer webis passed through a nip 250 and through one or more chilling rollers 260to embed the reinforcing scrim layer 130 into the extruded polymersecondary backing layer 120 and to cool and harden the extruded polymersecondary backing layer 120. The cooled web is then cut into individualcarpet tiles 100 for evaluation.

It was found that the carpet tile 100 provided according to this exampleconstruction exhibited exceptional flatness and dimensional stabilitycharacteristics, while retaining a total weight of approximately between40-70 ounces per square yard, and preferably approximately between 54-57ounces per square yard, such as at least approximately 55 ounces persquare yard.

CONCLUSION

Many modifications and other embodiments will come to mind to oneskilled in the art to which this disclosure pertains having the benefitof the teachings presented in the foregoing descriptions and theassociated drawings. Therefore, it is to be understood that thedisclosure is not to be limited to the specific embodiments disclosedand that modifications and other embodiments are intended to be includedwithin the scope of the appended claims. Although specific terms areemployed herein, they are used in a generic and descriptive sense onlyand not for purposes of limitation.

That which is claimed:
 1. A carpet tile having an upper surface and anopposite bottom surface, wherein the bottom surface is an outermostbottom surface of the carpet tile, the carpet tile comprising: afacecloth comprising a primary backing and a plurality of face yarnsextending through the primary backing, wherein the facecloth defines theupper surface of the carpet tile; an extruded polymer secondary backinglayer having a top surface bonded to the facecloth and an oppositebottom surface, wherein the bottom surface of the extruded polymersecondary backing layer is partially exposed at the outermost bottomsurface of the carpet tile; and a reinforcing scrim layer comprising aplurality of woven fibers, wherein the reinforcing scrim layer is bondedto the bottom surface of the extruded polymer secondary backing layer,and the reinforcing scrim layer is partially exposed at the outermostbottom surface of the carpet tile.
 2. The carpet tile of claim 1,wherein the plurality of woven fibers of the reinforcing scrim layercomprise at least one of: glass fibers or polymer fibers.
 3. The carpettile of claim 2, wherein the plurality of woven fibers comprise polymerfibers comprising sheathed polyester core fibers.
 4. The carpet tile ofclaim 2, wherein the plurality of woven fibers comprise glass fibershaving a nonirritating coating.
 5. The carpet tile of claim 4, whereinthe nonirritating coating comprises polyethylene.
 6. The carpet tile ofclaim 1, wherein the reinforcing scrim layer comprises a plurality ofnonwoven fibers.
 7. The carpet tile of claim 1, wherein the reinforcingscrim layer comprises a plurality of polymer fibers and a plurality ofglass fibers.
 8. The carpet tile of claim 1, wherein the extrudedpolymer secondary backing comprises a polyolefin.
 9. The carpet tile ofclaim 8, wherein the extruded polymer secondary backing comprisesbetween about 10-40 wt % polyolefin.
 10. The carpet tile of claim 9,wherein the extruded polymer secondary backing comprises between about20-80 wt % of a filler material.
 11. The carpet tile of claim 1, whereinthe weight of the carpet tile is between about 40-70 ounces per squareyard.
 12. The carpet tile of claim 11, wherein the weight of the carpettile is between about 50-60 ounces per square yard.
 13. The carpet tileof claim 1, wherein the facecloth further comprises a primary backingpre-coat layer between the primary backing layer and the extrudedpolymer secondary backing layer.